Pyrimidine addiction: an Achilles' heel of NF2-altered mesothelioma

Our plain-English summary of Pyrimidine addiction: an Achilles' heel of NF2-altered mesothelioma, by J. Jia, G.T. Stathopoulos (EMBO Molecular Medicine, 2025).

The study

• Authors: J. Jia, G.T. Stathopoulos
• Journal: EMBO Molecular Medicine
• Published: 2025;17(9):2165-2167
• Cited by: 1 article, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Therapeutic options for patients with mesothelioma remain scarce and five-year survival is a meager ten percent. According to data from three large studies, 36% of mesotheliomas harbor neurofibromatosis 2 (NF2) mutations or loss (https://bit.ly/4nGcRXk; accessed on 06.30.2025), yet no targeted therapy exists for this molecular subtype of the disease. In the current issue of EMBO Molecular Medicine, Xu et al, demonstrate that NF2-deficiency of mesothelioma cells releases an NF2-mediated Hippo-pathway restraint, activates the Yes-associated protein (YAP)–carbamoyl-phosphate synthetase 2, aspartate transcarbamylase, and dihydroorotase (CAD)/dihydroorotate dehydrogenase (DHODH) axis, and drives addiction to high-flux de novo pyrimidine biosynthesis (Xu et al, 2025). Moreover, the authors elegantly show that DHODH inhibitors elicit robust antitumor activity against NF2-altered mesothelioma and exhibit strong synergy with cisplatin, opening a new translational avenue for this tumor subtype.

In plain English

This article is a short commentary (a "News & Views" piece), not an original study. The authors discussed a separate laboratory study by Xu and colleagues, published in the same 2025 issue, on mesothelioma cells that have lost NF2 function. As the commentary reported it, Xu and colleagues found that NF2-deficient mesothelioma formed a distinct subtype with increased production of pyrimidines, which are building blocks needed to copy DNA. A protein called YAP bound directly to control regions of two enzyme genes, CAD and DHODH, and pyrimidine production doubled. In laboratory experiments, blocking CAD or DHODH reduced the survival and growth of NF2-deficient cells, and high amounts of uridine fully reversed the cells' sensitivity to DHODH blockade. In experiments in living organisms, drugs that block DHODH worked together with the chemotherapy drug cisplatin. According to Xu and colleagues, roughly half of mesotheliomas showed this pyrimidine-high pattern, which was linked to the poorest prognosis. The authors concluded that this work offers a possible new treatment opportunity. They also suggested testing such treatments in KRAS-altered mesotheliomas. Asbestos exposure was not studied.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Commentary (News & Views) on another study (Xu et al, 2025, same issue); no new data
• Who was studied: The authors did not study any people. The commentary discusses laboratory (in vitro) and preclinical model work by Xu et al on NF2-deficient mesothelioma cells.
• Exposure: No asbestos exposure was studied. The subject is loss of NF2 function and drugs that block the enzyme DHODH, alone and combined with cisplatin, as tested by Xu et al.
• Main results:
  • As reported in the commentary, Xu et al found that NF2 deficiency marks a distinct mesothelioma subtype with up-regulated de novo pyrimidine biosynthesis.
  • Xu et al reported that YAP directly binds the CAD promoter and a DHODH enhancer.
  • Xu et al reported that coordinated up-regulation of CAD and DHODH doubles pyrimidine pathway flux.
  • In Xu et al's in vitro experiments, genetic silencing or drug inhibition of CAD or DHODH compromised cell viability, growth and proliferation, specifically in NF2-deficient cells.
  • In Xu et al's work, the vulnerability of NF2-deficient cells to DHODH blockade could be fully rescued by high exogenous uridine. This rescue is reported for DHODH blockade only.
  • Xu et al reported in vivo synergy of DHODH inhibitors with cisplatin.
  • According to Xu et al, roughly half of mesotheliomas display a pyrimidine-high phenotype. The commentary describes this phenotype as driven by NF2 deficiency, with high CAD/DHODH expression and the poorest prognosis.
• The authors' conclusion: The authors concluded that Xu et al's work delineates a druggable metabolic addiction of NF2-deficient mesothelioma to pyrimidine and offers a novel translational opportunity to treat this neoplasm. They also suggested that such regimens be tested against KRAS-altered mesotheliomas.

Topics

Medical terms in this study, explained in our Lexicon: Mesothelioma, Targeted Therapy, De Novo, Cisplatin.

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